A simple electronic device for optogalvanic and absorption spectroscopy of atoms in a commercial hollow cathode discharge lamp

Abstract

A simple, low-noise DC power supply was built in-house has been demonstrated in this work to control a commercial hollow cathode discharge lamp. This device is able to produce output voltages of up to 400 Volts at up to 50 mA current in where the current is stabilised by an active current sink. The unit also incorporated an AC coupled low-noise amplifier to detect the optogalvanic signal when excitation resonance takes place in the discharge lamp. Experiment has been performed using a single mode diode laser to investigate selected lines of argon (~772 nm) in the commercial hollow cathode discharge lamp which can be used for the optogalvanic and absorption techniques by sending the beams in a perpendicular direction to the cylinder axis of the discharge lamp, in-between its anode and cathode. It is even possible, to record different techniques simultaneously, namely the absorption and optogalvanic spectra.